<s>
The	O
Visual	B-Application
Memory	I-Application
Unit	I-Application
(	O
VMU	B-Application
)	O
,	O
also	O
referred	O
to	O
as	O
the	O
(	O
VMS	O
)	O
in	O
Japan	O
and	O
Europe	O
,	O
is	O
the	O
primary	O
memory	B-Device
card	I-Device
produced	O
by	O
Sega	O
for	O
the	B-Operating_System
Dreamcast	I-Operating_System
home	B-Device
video	I-Device
game	I-Device
console	I-Device
.	O
</s>
<s>
The	O
device	O
features	O
a	O
monochrome	O
liquid	B-Device
crystal	I-Device
display	I-Device
(	O
LCD	B-Device
)	O
,	O
multiplayer	O
gaming	O
capability	O
(	O
via	O
connectors	O
at	O
the	O
top	O
)	O
,	O
second	O
screen	O
functionality	O
,	O
a	O
real-time	O
clock	O
,	O
file	B-Application
manager	I-Application
,	O
built-in	O
flash	B-Device
memory	I-Device
,	O
and	O
sound	O
capability	O
.	O
</s>
<s>
Prior	O
to	O
the	O
launch	O
of	O
the	B-Operating_System
Dreamcast	I-Operating_System
,	O
a	O
special	O
Godzilla	O
edition	O
VMU	B-Application
,	O
preloaded	O
with	O
a	O
virtual	O
pet	O
game	O
,	O
was	O
released	O
on	O
July	O
30	O
,	O
1998	O
,	O
in	O
Japan	O
.	O
</s>
<s>
While	O
its	O
most	O
basic	O
function	O
is	O
as	O
a	O
removable	O
storage	O
device	O
,	O
the	O
VMU	B-Application
may	O
also	O
serve	O
as	O
an	O
auxiliary	O
display	O
during	O
normal	O
gameplay	O
and	O
,	O
through	O
the	O
use	O
of	O
additional	O
software	O
(	O
distributed	O
as	O
extras	O
on	O
Dreamcast	B-Operating_System
GD-ROMs	B-Device
)	O
,	O
acts	O
as	O
a	O
handheld	B-Application
game	I-Application
console	I-Application
.	O
</s>
<s>
Console-like	O
features	O
of	O
the	O
VMU	B-Application
include	O
a	O
screen	O
,	O
speaker	O
,	O
proper	O
directional	B-Device
pad	I-Device
,	O
four	O
action	O
buttons	O
,	O
the	O
ability	O
to	O
connect	O
and	O
interact	O
with	O
other	O
VMUs	B-Application
,	O
and	O
the	O
ability	O
to	O
download	O
additional	O
games	O
.	O
</s>
<s>
While	O
the	O
standard	O
VMU	B-Application
is	O
white	O
,	O
colors	O
were	O
expanded	O
to	O
include	O
many	O
variations	O
.	O
</s>
<s>
Japan	O
even	O
saw	O
the	O
release	O
of	O
branded	O
VMUs	B-Application
,	O
such	O
as	O
those	O
by	O
Sonic	O
Team	O
,	O
Capcom	O
and	O
Hello	O
Kitty	O
.	O
</s>
<s>
For	O
use	O
as	O
a	O
memory	B-Device
card	I-Device
and	O
second	O
screen	O
,	O
the	O
VMU	B-Application
is	O
plugged	O
directly	O
into	O
one	O
of	O
two	O
slots	O
on	O
a	O
Dreamcast	B-Operating_System
controller	O
(	O
up	O
to	O
two	O
VMUs	B-Application
may	O
be	O
plugged	O
in	O
each	O
controller	O
,	O
and	O
eight	O
VMUs	B-Application
per	O
Dreamcast	B-Operating_System
console	O
)	O
.	O
</s>
<s>
Upon	O
initial	O
use	O
,	O
the	O
player	O
is	O
prompted	O
to	O
set	O
the	O
date	O
and	O
time	O
,	O
and	O
then	O
select	O
from	O
a	O
group	O
of	O
bitmap	O
images	O
to	O
serve	O
as	O
the	O
default	O
background	O
for	O
the	O
VMU	B-Application
(	O
various	O
Dreamcast	B-Operating_System
titles	O
may	O
offer	O
players	O
additional	O
background	O
images	O
for	O
the	O
unit	O
)	O
.	O
</s>
<s>
This	O
image	O
is	O
displayed	O
while	O
the	B-Operating_System
Dreamcast	I-Operating_System
console	O
is	O
in	O
the	O
operating	O
system	O
menu	O
.	O
</s>
<s>
When	O
operated	O
independently	O
of	O
the	B-Operating_System
Dreamcast	I-Operating_System
console	O
,	O
the	O
VMU	B-Application
acts	O
as	O
a	O
file	B-Application
manager	I-Application
,	O
clock/calendar	O
(	O
with	O
selectable	O
clock	O
animations	O
)	O
,	O
and	O
handheld	B-Application
game	I-Application
console	I-Application
.	O
</s>
<s>
VMUs	B-Application
may	O
also	O
connect	O
to	O
each	O
other	O
directly	O
to	O
facilitate	O
file	O
transfer	O
or	O
multiplayer	O
gaming	O
.	O
</s>
<s>
The	O
VMU	B-Application
runs	O
on	O
two	O
CR-2032	B-Algorithm
lithium	O
batteries	O
which	O
are	O
inserted	O
into	O
the	O
rear	O
of	O
the	O
VMU	B-Application
under	O
a	O
screw-secured	O
lid	O
.	O
</s>
<s>
Without	O
battery	O
power	O
,	O
the	O
VMU	B-Application
still	O
functions	O
as	O
a	O
memory	B-Device
card	I-Device
and	O
auxiliary	O
display	O
,	O
but	O
cannot	O
play	O
downloaded	O
mini-games	O
.	O
</s>
<s>
Additionally	O
,	O
a	O
VMU	B-Application
without	O
battery	O
power	O
will	O
beep	O
when	O
the	B-Operating_System
Dreamcast	I-Operating_System
is	O
powered	O
on	O
(	O
if	O
the	O
VMU	B-Application
is	O
inserted	O
into	O
a	O
connected	O
Dreamcast	B-Operating_System
controller	O
)	O
.	O
</s>
<s>
Memory	O
:	O
128KB	O
flash	B-Device
memory	I-Device
.	O
</s>
<s>
The	O
VMU	B-Application
has	O
128KB	O
of	O
flash	B-Device
memory	I-Device
,	O
but	O
by	O
default	O
28KB	O
is	O
reserved	O
for	O
system	O
use	O
leaving	O
100KB	O
for	O
data	O
storage	O
,	O
which	O
is	O
divided	O
into	O
200	O
'	O
blocks	O
 '	O
–	O
1	O
block	O
equaling	O
512	O
bytes	O
.	O
</s>
<s>
In	O
recent	O
years	O
homebrew	O
programs	O
like	O
Dream	O
Explorer	O
(	O
aka	O
VMU	B-Application
Tool	O
)	O
have	O
allowed	O
users	O
to	O
unlock	O
an	O
extra	O
44	O
blocks	O
(	O
22KB	O
)	O
of	O
this	O
reserved	O
space	O
increasing	O
the	O
overall	O
VMU	B-Application
capacity	O
to	O
244	O
blocks	O
.	O
</s>
<s>
However	O
,	O
a	O
handful	O
of	O
games	O
might	O
be	O
unable	O
to	O
detect	O
the	O
memory	B-Device
card	I-Device
if	O
this	O
is	O
done	O
,	O
although	O
none	O
have	O
been	O
reported	O
apart	O
from	O
DreamKey/DreamPassport	O
and	O
Metropolis	B-Application
Street	I-Application
Racer	I-Application
.	O
</s>
<s>
Several	O
titles	O
for	O
the	B-Operating_System
Dreamcast	I-Operating_System
include	O
mini-games	O
that	O
can	O
be	O
downloaded	O
onto	O
a	O
VMU	B-Application
.	O
</s>
<s>
The	O
Sonic	B-Application
Adventure	I-Application
series	O
,	O
for	O
instance	O
,	O
include	O
the	O
Chao	O
Adventure	O
mini-games	O
(	O
Chao	O
Adventure	O
and	O
Chao	O
Adventure	O
2	O
which	O
features	O
more	O
activities	O
and	O
items	O
)	O
.	O
</s>
<s>
In	O
the	O
games	O
,	O
players	O
can	O
transfer	O
Chao	O
eggs	O
to	O
the	O
VMU	B-Application
and	O
partake	O
in	O
various	O
activities	O
to	O
increase	O
the	O
stats	O
of	O
their	O
hatched	O
Chao	O
,	O
whereupon	O
they	O
can	O
upload	O
their	O
improved	O
Chao	O
back	O
into	O
the	B-Operating_System
Dreamcast	I-Operating_System
game	O
.	O
</s>
<s>
Sega	B-Application
GT	I-Application
includes	O
Pocket	O
GT	O
,	O
a	O
top-down	O
racer	O
in	O
the	O
style	O
of	O
the	O
8-bit	O
SpyHunter	B-Application
games	O
.	O
</s>
<s>
In	O
other	O
video	O
games	O
,	O
statistics	O
such	O
as	O
the	O
current	O
health	O
condition	O
are	O
displayed	O
on	O
the	O
VMU	B-Application
for	O
convenience	O
(	O
as	O
in	O
Resident	B-Application
Evil	I-Application
:	I-Application
Code	I-Application
Veronica	I-Application
)	O
or	O
to	O
enhance	O
multi-player	O
gaming	O
(	O
for	O
example	O
,	O
NFL	B-Application
2K2	I-Application
allowed	O
the	O
VMU	B-Application
to	O
display	O
secret	O
plays	O
not	O
viewable	O
to	O
other	O
players	O
)	O
.	O
</s>
<s>
There	O
are	O
also	O
numerous	O
homebrew	O
games	O
,	O
original	O
creations	O
and	O
ports	O
of	O
famous	O
games	O
,	O
that	O
are	O
freely	O
available	O
on	O
the	O
internet	O
and	O
can	O
be	O
installed	O
and	O
played	O
on	O
a	O
VMU	B-Application
.	O
</s>
<s>
These	O
games	O
include	O
:	O
Metroid	B-Device
,	O
VMU	B-Application
Mini	O
Pacman	O
,	O
Breakout	B-Application
,	O
Space	B-Application
Invaders	I-Application
,	O
Tetris	B-Device
,	O
VMU	B-Application
Fighter	O
(	O
a	O
side-scrolling	O
shoot	O
'	O
em	O
up	O
)	O
,	O
VMU	B-Application
Chao	O
Editor	O
1	O
and	O
VMU	B-Application
Chao	O
Editor	O
2	O
(	O
to	O
create	O
and	O
edit	O
the	O
player	O
's	O
own	O
Chao	O
)	O
,	O
VMU	B-Application
Football	O
(	O
an	O
American	O
football	O
game	O
)	O
,	O
VMU-a-Sketch	O
(	O
a	O
digital	O
Etch-a-sketch	O
pad	O
)	O
,	O
and	O
3D	O
FPS	O
(	O
a	O
first-person-shooter	O
)	O
.	O
</s>
<s>
Dreamcast	B-Operating_System
game	O
VMU	B-Application
minigame	O
In-game	O
features	O
Cardcaptor	O
Sakura	O
:	O
Tomoyo	O
no	O
Video	O
Daisakusen	O
Three	O
mini-games	O
:	O
</s>
<s>
Ammo	O
count	O
Evil	B-Application
Twin	I-Application
:	I-Application
Cyprien	I-Application
's	I-Application
Chronicles	I-Application
Four	O
mini-games	O
(	O
downloadable	O
)	O
Evolution	B-Application
:	I-Application
The	I-Application
World	I-Application
of	I-Application
Sacred	I-Application
Device	I-Application
Health	O
condition	O
Evolution	B-Application
2	I-Application
:	I-Application
Far	I-Application
Off	I-Application
Promise	I-Application
12-hour	O
clock	O
F355	B-Application
Challenge	I-Application
Arcade	O
connectivity	O
Godzilla	B-Application
Generations	I-Application
(	O
Japanese	O
version	O
)	O
Three	O
mini-games	O
:	O
</s>
<s>
Mothra	O
Dream	O
Battle	O
Jet	B-Application
Set	I-Application
Radio	I-Application
/	O
Jet	B-Application
Grind	I-Application
Radio	I-Application
Graffiti	O
transfer	O
Marvel	B-Application
vs.	I-Application
Capcom	I-Application
2	I-Application
:	I-Application
New	I-Application
Age	I-Application
of	I-Application
Heroes	I-Application
Transfer	O
characters	O
,	O
colors	O
and	O
stages	O
Arcade	O
connectivity	O
Namco	B-Device
Museum	I-Device
Pac-It	O
NBA	B-Application
2K	I-Application
/	O
2K1	B-Application
/	O
2K2	B-Application
Team	O
statistics	O
NFL	O
2K	O
/	O
2K1	B-Application
/	O
2K2	B-Application
/	O
Blitz	B-Application
Secret	O
plays	O
Pop'n	B-Application
Music	I-Application
series	O
Pop'n	B-Application
Music	I-Application
Anywhere	O
mini-game	O
Virtual	O
Pop'n	B-Application
Music	I-Application
controller	O
Power	B-Application
Stone	I-Application
Three	O
mini-games	O
:	O
</s>
<s>
Multiple	O
Dreamcast	B-Operating_System
memory	B-Device
cards	I-Device
with	O
no	O
VMU	B-Application
features	O
have	O
been	O
released	O
.	O
</s>
<s>
Some	O
have	O
the	O
same	O
128	O
KB	O
storage	O
as	O
the	O
VMU	B-Application
,	O
equivalent	O
to	O
200	O
blocks	O
,	O
while	O
others	O
have	O
multiple	O
"	O
pages	O
"	O
with	O
each	O
acting	O
as	O
a	O
128	O
KB	O
memory	B-Device
card	I-Device
.	O
</s>
<s>
In	O
the	O
latter	O
case	O
,	O
a	O
button	O
or	O
switch	O
allows	O
the	O
gamer	O
to	O
select	O
the	O
desired	O
memory	B-Device
card	I-Device
.	O
</s>
<s>
This	O
is	O
due	O
to	O
the	B-Operating_System
Dreamcast	I-Operating_System
having	O
a	O
limit	O
of	O
128	O
KB	O
per	O
individual	O
memory	B-Device
card	I-Device
.	O
</s>
<s>
Sega	O
released	O
an	O
official	O
4x	O
Memory	B-Device
Card	I-Device
which	O
offered	O
four	O
times	O
the	O
data	O
storage	O
of	O
a	O
standard	O
VMU	B-Application
,	O
with	O
800	O
blocks	O
.	O
</s>
<s>
It	O
was	O
released	O
in	O
Japan	O
on	O
December	O
14	O
,	O
2000	O
,	O
as	O
"	O
Memory	B-Device
Card	I-Device
4X	O
"	O
,	O
and	O
in	O
the	O
US	O
as	O
"	O
4x	O
Memory	B-Device
Card	I-Device
"	O
.	O
</s>
<s>
A	O
limited	O
edition	O
Phantasy	B-Application
Star	I-Application
Online	I-Application
4x	O
Memory	B-Device
Card	I-Device
was	O
also	O
released	O
in	O
Japan	O
to	O
coincide	O
with	O
the	O
game	O
's	O
release	O
.	O
</s>
<s>
It	O
was	O
coloured	O
blue	O
and	O
featured	O
the	O
Phantasy	B-Application
Star	I-Application
Online	I-Application
logo	O
printed	O
onto	O
the	O
casing	O
.	O
</s>
<s>
The	O
4x	O
Memory	B-Device
Card	I-Device
did	O
not	O
make	O
it	O
to	O
retail	O
in	O
Europe	O
,	O
despite	O
a	O
planned	O
release	O
(	O
along	O
with	O
the	B-Operating_System
Dreamcast	I-Operating_System
Broadband	O
Adapter	O
which	O
was	O
also	O
unreleased	O
in	O
Europe	O
)	O
due	O
to	O
the	B-Operating_System
Dreamcast	I-Operating_System
's	O
unforeseeably	O
short	O
lifespan	O
–	O
although	O
unofficial	O
third	O
party	O
4x	O
Memory	B-Device
Cards	I-Device
were	O
released	O
in	O
Europe	O
.	O
</s>
<s>
The	O
Nexus	B-Application
Memory	I-Application
Card	I-Application
is	O
a	O
third	O
party	O
version	O
of	O
the	O
Visual	B-Application
Memory	I-Application
Unit	I-Application
that	O
features	O
four	O
times	O
the	O
memory	O
of	O
a	O
stock	O
VMU	B-Application
with	O
800	O
blocks	O
(	O
4	O
megabit	O
/	O
512	O
kilobytes	O
)	O
but	O
lacks	O
an	O
LCD	B-Device
screen	I-Device
.	O
</s>
<s>
The	O
Nexus	B-Application
Memory	I-Application
Card	I-Application
is	O
slightly	O
larger	O
than	O
the	O
normal	O
VMU	B-Application
and	O
can	O
be	O
connected	O
to	O
a	O
personal	B-Device
computer	I-Device
by	O
USB	B-Protocol
,	O
Parallel	B-Protocol
or	O
Serial	B-Protocol
cable	O
.	O
</s>
<s>
Nyko	O
released	O
two	O
memory	B-Device
cards	I-Device
for	O
the	B-Operating_System
Dreamcast	I-Operating_System
:	O
the	O
Jumbo	O
Memory	O
Pak	O
X2	O
with	O
twice	O
the	O
storage	O
as	O
a	O
VMU	B-Application
,	O
and	O
the	O
Hyperpak	O
with	O
four	O
times	O
the	O
storage	O
.	O
</s>
<s>
The	O
Performance	O
Memory	B-Device
Card	I-Device
was	O
a	O
third-party	O
basic	O
memory	B-Device
card	I-Device
with	O
the	O
same	O
200	O
blocks	O
of	O
storage	O
as	O
a	O
VMU	B-Application
.	O
</s>
<s>
The	O
Performance	O
Mega	O
Memory	B-Device
Card	I-Device
acted	O
like	O
a	O
4X	O
Memory	B-Device
Card	I-Device
.	O
</s>
<s>
It	O
used	O
a	O
switch	O
on	O
its	O
back	O
to	O
select	O
the	O
desired	O
memory	B-Device
card	I-Device
"	O
page	O
"	O
.	O
</s>
<s>
Unlike	O
other	O
memory	B-Device
cards	I-Device
however	O
,	O
the	O
Performance	O
model	O
had	O
to	O
be	O
removed	O
from	O
the	O
controller	O
before	O
the	O
"	O
page	O
"	O
could	O
be	O
switched	O
.	O
</s>
<s>
In	O
a	O
10-year	O
retrospective	O
,	O
GamesRadar	O
called	O
the	O
VMU	B-Application
"	O
one	O
of	O
our	O
favorite	O
storage	O
devices	O
"	O
.	O
</s>
